In an isolated secret village hidden on Ninja Mountain, several Tengu and the wise Ninja Master lives with six ninjas he has trained to their unique potentials. Suddenly, the peace that has lasted in the empire for over three centuries is shattered. Strange storms begin appearing across the land, earthquakes and floods explode in the flatlands, and forest animals are being captured by mysterious beings for unknown purposes. The cause of these strange disturbances is the Evil Samurai Warlord, who has returned from exile and has begun building an army.
Not yet knowing about the Warlord's involvement in the plan, the Ninja Master sends ninjas out to find the source of the storms, but none of them return. Soon, he is left with his two least trained ninjas: Hiro and Futo. However, knowing that there is no choice, the Ninja Master has them finish their training quickly and leave the village to investigate the storms and mysterious creatures. The group, led by Hiro, learns of the Warlord's plan and go out to defeat the Warlord, freeing the missing ninjas along the way.
When Hiro finally gets to the Samurai Warlord, he engages in combat and eventually defeats him. The Warlord loses his power and falls into a crevice, consumed by the darkness within. His armies are returned into forest animals, the strange storms dissolve, and peace returns to the world. The six ninjas begin the quest home, likely encountering adventures along the way.
- Hiro - Hiro is the youngest of all Mini Ninjas, whose talents with Kuji magic are second only to the Evil Warlord. Hiro was found as an infant by the Ninja Master and might become the greatest ninja ever. He is available from the start of the game and is the only player character that can use the various magic spells. His main weapon is a ninja sword and his special move is a lock on attack that stops time and automatically attacks the enemies that have been selected.He is also the only character you can use to fight bosses and the first playable character.To sum it up, he is vey special.
- Futo - Futo is the second ninja in the game and is found on the first level. He carries a large wooden hammer and boasts great strength, being the only Mini Ninja who can take on the huge Samurai Clubmen, but is also the slowest one. His special move is to roll into a ball and attack.
- Suzume - Suzume is a female ninja, perhaps the most agile and swift ninja in the tribe. She uses a flute, which was left for her by her mysterious mother. Her main attacks consist of high kicks and flute strikes that can stun enemies, while her special attack is playing her flute to mesmerize all nearby enemies. She is the first ninja rescued by Hiro on his quest, and is apparently somewhat a love interest for him.She also likes him secretly.
- Shun - Shun is the stealthiest Mini Ninja and is the second ninja the player rescues, after Suzume. Shun is the most tense of all the Mini Ninjas but he still maintains the unique ninja skill of calming himself to utter silence when it requires it. Shun wears camouflage and uses a bow and arrows. His special attack enables him to tie a powerful explosive to the shaft of an arrow. He is the only ninja who speaks, talking to himself in Japanese as he sneaks, leaps, and fires his arrows.
- Tora - Tora, who believes to be a tiger ("Tora" in Japanese), is by far the most energetic of the Ninjas, furious in combat. He was left by his parents on the steps of the Ninja Village. Tora's favorite weapon is a pair of self-made tiger claws, which he uses to great effect. He can throw himself into a "tiger dash", propelling him forward at a great speeds when large distances need to be covered, pouncing into a spinning claw attack.
- Kunoichi - Kunoichi is the younger and less mature of the girls. Her weapon is a naginata, which she uses as a prop for her acrobatic moves. Her special attacks spins her spear above her head, drawing upon the magical energy infused within the weapon, before unleashing a spinning attack on her foes. Kunoichi is very quiet, does not reveal much about herself and is a bit of a loner. She looks up to Suzume as an older sister and adores Hiro.
- Tengu - Mysterious birdmen of legend and fokelore, they are encountered throughout the game as the player progresses. Non-combatants who are either along the road or in front of a temple, they give advice, sell various bombs and potion recepies, or ask for small favors which in return they reward the player with an item.
- Samurai Warlord
- Samurai Swordsmen
- Samurai Captains
- Samurai Archers
- Samurai Spearmen
- Samurai Clubmen
- Hatted Samurai
Mini Ninjas has received positive reviews from critics, getting 7.5/10 from GameSpot, 8/10 from IGN Entertainment, and 4/5 from The Guardian. It has recieved praise for it's family-fun elements and charm.
The game is a third-person action-adventure game with a maximum of six characters which the player can switch on and off, each with their own unique abilities and weapons. Only one character can be used at a time, but they can be switched off easily. All characters are able to use caltrops, shurikens, bombs, and special attacks aside their custom abilites. There are potions that are either found or made using ingredients that restore health or allow special abilities. The game does not contain any graphic violence, as defeating Samurai will transform them back into forest animals. There are a total of 100 Jizo Statues that can be used for special achievements or trophies, encouraging level exploration.
The main protagonist Hiro is the only one who is able to use Kuji magic, which he uses to perform spells which allow him to locate shrines, possess animals, camoflauge himself as a bush, summon the elements to create special attacks, and slow time. He is also the only one who can use the fishing rod and engage in boss fights. There are a total of 22 levels in the game. The player has a heart system, with three hearts at the beginning and a maximum of seven hearts by the end. Special energy spheres are generated when enemies are defeated, which either give experience points, recharge Ki energy, or activate a special attack.
In March 2012, it was announced that Square Enix, which presides over Eidos Interactive, had filed a trademark in Europe for a possible sequel called "Mini Ninjas: Hiro's Adventure". Square Enix later confirmed the sequel in May 2012.